Nucleosome structural studies

Chromatin plays a fundamental role in eukaryotic genomic regulation, and the increasing awareness of the importance of epigenetic processes in human health and disease emphasizes the need for understanding the structure and function of the nucleosome. Recent advances in chromatin structural studies, including the first structures of nucleosomes containing the Widom 601 sequence and the structure of a chromatin protein-nucleosome assembly, have provided new insight into stretching of nucleosomal DNA, nucleosome positioning, binding of metal ions, drugs and therapeutic candidates to nucleosomes, and nucleosome recognition by nuclear proteins. These discoveries ensure promising future prospects for unravelling structural attributes of chromatin.     

中国野生牡丹研究（一）芍药属牡丹组新分类群

牡丹为我国特产珍贵花树和药用树种,已有1500余年栽培历史,建国以来,各地栽培品种已达500余个。 有关牡丹分类的主要研究成果多为西方科学家根据18—19世纪从我国引种到英、美、法等国的栽培牡丹和腊叶标本加以描述和定名。 作者近几年来在安徽、河南、湖南、山西、陕西、甘肃、四川、云南等地对我国野生牡丹进行了较广泛的调查和研究。 本文发表3个新种和1个新等级,这对研究我国栽培牡丹的起源和栽培品种的自然分类,发掘、保护、利用我国珍稀野生牡丹基因资源,培育新品种,扩大牡丹栽培地区等方面提供了科学理论依据。     

异源细胞质小麦育种技术

采用核置换回交技术创制出新型异源细胞质小麦 ,通过对同质异核系、同核异质系的比较研究 ,证明部分异源细胞质对小麦产量性状、籽粒品质、耐盐性、抗病性等可以产生有益的遗传效应 ,其中以粗厚山羊草、节节麦、和偏凸山羊草的细胞质效应最好 .核质杂种优势的有无和大小因具体的核质组合和性状而不同 .培育成功优质、抗病、抗逆、异源细胞质小麦新种质 .粗厚山羊草细胞质小麦新品种在生产试验、示范、区域试验中表现突出 ,通过品种预审 .异源细胞质小麦遗传变异和利用的探讨对新品种选育和遗传学研究有重要价值 .     

Serelaxin inhibits differentiation and fibrotic behaviors of cardiac fibroblasts by suppressing ALK-5/Smad2/3 signaling pathway

Serelaxin, a recombinant form of human relaxin-2, is currently regarded as a novel drug for treatment of acute heart failure. However, whether therapeutic effects of serelaxin are achieved by inhibiting cardiac fibrosis remains unclear. In this study, we investigate effects of serelaxin on inhibiting cardiac fibrosis. Cardiac fibroblasts (CFs) were isolated from the hearts of adult rats. Effects of serelaxin on differentiation of CFs towards myofibroblasts (MFs) and their fibrotic behaviors after induction with TGF-β1 were examined. Synthesis and degradation of collagens, secretion of IL-10, and expression of ALK-5 and p-Smad2/3 of TGF-β1-induced cells were assessed after treatment with serelaxin. Serelaxin inhibited differentiation of TGF-β1-induced CFs towards MFs, and reduced proliferation and migration of the induced cells. Moreover, serelaxin down-regulated expression of collagen I/III and TIMP-2, and up-regulated expression of MMP-2 and MMP-9 in the cells. After treatment with serelaxin, activity of MMP-2 and MMP-9 and secretion of IL-10 increased, expression of ALK-5 and the level of Smad2/3 phosphorylation was reduced significantly. These results suggest that serelaxin can inhibit differentiation of TGF-β1-induced CFs towards MFs, reduce production of collagens by suppressing ALK-5/Smad2/3 signaling pathway, and enhance extracellular matrix degradation by increasing MMP-2/TIMP-2 ratio and IL-10 secretion. Serelaxin may be a potential therapeutic drug for inhibiting cardiac fibrosis.     

Genome-wide analysis of the Chinese sturgeon sox gene family: identification,characterisation and expression profiles of different tissues

The sox family is assumed to be responsible for a number of developmental systems. Genome sequencing technology makes it possible to scan sox genes and conduct characteristic analyses of different species. In fish, full characterisation of sox genes at the genome-wide level has been reported for pufferfish Takifugu rubripes, medaka Oryzias latipes, tilapia Oreochromis niloticus and channel catfish Ictalurus punctatus. However, no systematic investigation of the sox family in sturgeons (Acipenseridae) has been reported to date. This study conducted genome-wide identification of the sox genes in the Chinese sturgeon Acipenser sinensis and profiled their tissue distribution between male and female individuals. In total, 19 sox genes were identified, including soxb1, b2, c, d, e, f and h, in the Chinese sturgeon. Genomic structure analysis indicated relatively conserved exon–intron structures in each sox group and phylogenetic analysis supported the previous classification of the sox family. Most of the sox genes showed a tissue-specific expression pattern, indicating the possible involvement of Chinese sturgeon sox genes at different developmental processes such as cardiac and gonadal development. This study provides a comprehensive resource of Chinese sturgeon sox genes and enables a better understanding of the evolution and function of the sox family.     

Modeling Calcium Wave Based on Anomalous Subdiffusion of Calcium Sparks in Cardiac Myocytes

sparks and waves play important roles in calcium release and calcium propagation during the excitation-contraction (EC) coupling process in cardiac myocytes. Although the classical Fick’s law is widely used to model sparks and waves in cardiac myocytes, it fails to reasonably explain the full-width at half maximum(FWHM) paradox. However, the anomalous subdiffusion model successfully reproduces sparks of experimental results. In this paper, in the light of anomalous subdiffusion of sparks, we develop a mathematical model of calcium wave in cardiac myocytes by using stochastic release of release units (CRUs). Our model successfully reproduces calcium waves with physiological parameters. The results reveal how concentration waves propagate from an initial firing of one CRU at a corner or in the middle of considered region, answer how large in magnitude of an anomalous spark can induce a wave. With physiological currents (2pA) through CRUs, it is shown that an initial firing of four adjacent CRUs can form a wave. Furthermore, the phenomenon of calcium waves collision is also investigated.     

Effect of ammonium-N on malic enzyme and lipid production in Rhodotorula glutinis grown on monosodium glutamate wastewater

Rhodotorula glutinis, an oil producing strain, can utilize monosodium glutamate (MSG) wastewater as a raw material for lipid production. The effects of ammonium-N in the MSG wastewater (ammonium 15,000–25,000?mg/L, COD 30,000–50,000?mg/L) on cell growth, lipid accumulation and malic enzyme activity of R. glutinis have been studied. Four initial ammonium sulfate concentrations in the medium were set, which were 20, 60, 100, and 140?g/L. With an increase in the ammonium sulfate concentration, the uptake of ammonia nitrogen and lipid accumulation increased while the biomass decreased at 72?h. The maximum value of ammonia nitrogen consumption reached 5.77?g/L for an initial ammonium sulfate concentration of 140?g/L at 72?h. In addition, 60?g/L ammonium sulfate concentration may be an appropriate concentration for R. glutinis cultivation. The activity of the malic enzyme was measured and the results showed that there was a linear relationship between the intracellular lipid content and the total malic enzyme activity.     

Homo- and hetero-dimerization of LPA/S1P receptors, OGR1 and GPR4

G protein coupled receptors (GPCRs) form homo- and hetero-dimers or -oligomers, which are functionally important. Lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are bioactive lysophopholipids involved in diverse biological processes. We have examined homo- and hetero-dimerization among three major LPA receptors (LPA(1-3)), three major S1P receptors (S1P(1-3)), as well as OGR1 and GPR4. Using LacZ complementation assays, we have shown that LPA receptors form homo- and hetero-dimers within the LPA receptor subgroup and hetero-dimers with other receptors (S1P(1-3) and GPR4). In addition, we have found that although GPR4 and OGR1 share more than 50% homology, GPR4 forms strong homo- and hetero-dimers with LPA and S1P receptors, but OGR1 forms very weak homo-dimer and relatively weak hetero-dimers with other receptors. Using chimeric receptors between GPR4 and OGR1, we have shown that different domains of GPR4 receptor are involved in its dimerization with different GPCRs and more than one domain may be involved in some of the complex formation. Our results suggest that when studying a signal transduction induced by a stimulus, not only is the expression and activation of its own receptor(s), but also the status of the interacting receptors should be taken into consideration.